Space.com - March 23, 2007
Astronomers just got their most detailed look yet at supersonic “bullets” of gas piercing through dense clouds of hydrogen gas in the Orion Nebula.
Each bullet [image] is about ten times the size of Pluto’s orbit around the Sun and travels through the clouds at up to 250 miles (400 kilometers) per second—or about a thousand times faster than the speed of sound...